Alternative formulas for synthetic dual system estimation in the 2000 census

The U.S. Census Bureau provides an estimate of the true population as a supplement to the basic census numbers. This estimate is constructed from data in a post-censal survey. The overall procedure is referred to as dual system estimation. Dual system estimation is designed to produce revised estimates at all levels of geography, via a synthetic estimation procedure. We design three alternative formulas for dual system estimation and investigate the differences in area estimates produced as a result of using those formulas. The primary target of this exercise is to better understand the nature of the homogeneity assumptions involved in dual system estimation and their consequences when used for the enumeration data that occurs in an actual large scale application like the Census. (Assumptions of this nature are sometimes collectively referred to as the ``synthetic assumption'' for dual system estimation.) The specific focus of our study is the treatment of the category of census counts referred to as imputations in dual system estimation. Our results show the degree to which varying treatment of these imputation counts can result in differences in population estimates for local areas such as states or counties.Comment: Published in at http://dx.doi.org/10.1214/193940307000000400 the IMS Collections (http://www.imstat.org/publications/imscollections.htm) by the Institute of Mathematical Statistics (http://www.imstat.org

An Overview of the Kauffman Firm Survey: Results From the 2004-2008 Data

Presents findings from longitudinal data on new businesses founded in 2004, including financing structure; products, services, and innovations; and characteristics of the owners. Examines indicators of growth and survival and effects of the recession

An Overview of the Kauffman Firm Survey: Results From the 2004-2007 Data

Based on surveys conducted over four years, provides an overview of trends among U.S. firms established in 2004 and the business and owner characteristics associated with survival and growth, including level of innovation, structure, and financing

Helsingør Statement on poly- and perfluorinated alkyl substances (PFASs)

In this discussion paper, the transition from long-chain poly- and perfluorinated alkyl substances (PFASs) to fluorinated alternatives is addressed. Long-chain PFASs include perfluoroalkyl carboxylic acids (PFCAs) with 7 or more perfluorinated carbons, perfluoroalkyl sulfonic acids (PFSAs) with 6 or more perfluorinated carbons, and their precursors. Because long-chain PFASs have been found to be persistent, bioaccumulative and toxic, they are being replaced by a wide range of fluorinated alternatives. We summarize key concerns about the potential impacts of fluorinated alternatives on human health and the environment in order to provide concise information for different stakeholders and the public. These concerns include, amongst others, the likelihood of fluorinated alternatives or their transformation products becoming ubiquitously present in the global environment; the need for more information on uses, properties and effects of fluorinated alternatives; the formation of persistent terminal transformation products including PFCAs and PFSAs; increasing environmental and human exposure and potential of adverse effects as a consequence of the high ultimate persistence and increasing usage of fluorinated alternatives; the high societal costs that would be caused if the uses, environmental fate, and adverse effects of fluorinated alternatives had to be investigated by publicly funded research; and the lack of consideration of non-persistent alternatives to long-chain PFASs

Analysis of dual system estimation in the 2000 decennial census

From a statistical point of view, the U.S. census is the most extensive sampling project. The accuracy of the census is of great interest to researchers, regulators, and the government. The Accuracy and Coverage Evaluation (A.C.E.) study was conducted to measure the overall and differential coverage of the U.S. population in census 2000. The A.C.E. involves two parts: the E-sample and the P-sample. A dual system estimation is used to obtain an estimate for the undercount for putatively homogenous groups called post-strata. A synthetic dual system estimate is finally produced for specific geographic regions. In this dissertation, we evaluate various aspects of the dual system methodology. There are two main assumptions in this process. First, the E-sample results and the P-sample results are statistically independent, i.e., there is no correlation bias. Second, the undercount rates are constant within post-strata across geographic areas, i.e., post-strata are actually homogeneous. In this dissertation, we develop a joint Poisson model to test these hypotheses. By means of a procedure involving bootstrap resampling of the log-likelihood ratio statistic and the EM algorithm, both hypotheses are rejected

Analysis of dual system estimation in the 2000 decennial census

From a statistical point of view, the U.S. census is the most extensive sampling project. The accuracy of the census is of great interest to researchers, regulators, and the government. The Accuracy and Coverage Evaluation (A.C.E.) study was conducted to measure the overall and differential coverage of the U.S. population in census 2000. The A.C.E. involves two parts: the E-sample and the P-sample. A dual system estimation is used to obtain an estimate for the undercount for putatively homogenous groups called post-strata. A synthetic dual system estimate is finally produced for specific geographic regions. In this dissertation, we evaluate various aspects of the dual system methodology. There are two main assumptions in this process. First, the E-sample results and the P-sample results are statistically independent, i.e., there is no correlation bias. Second, the undercount rates are constant within post-strata across geographic areas, i.e., post-strata are actually homogeneous. In this dissertation, we develop a joint Poisson model to test these hypotheses. By means of a procedure involving bootstrap resampling of the log-likelihood ratio statistic and the EM algorithm, both hypotheses are rejected

Histone deacetylase 6 interference protects mice against experimental stroke-induced brain injury via activating Nrf2/HO-1 pathway

Cerebral stroke is a fatal disease with increasing incidence. The study was to investigate the role and mechanism of Histone deacetylase 6 (HDAC6) on experimental stroke-induced brain injury. The recombinant shRNA-HDAC6 or scramble shRNA lentivirus was transfected to ICR mice. Then, the ischemia/reperfusion injury (I/RI) mice were constructed using middle cerebral artery occlusion (MCAO) method. Brain TTC staining was used to determine infarct areas. Serum levels of oxidative stress-related factors were detected by enzyme linked immunosorbnent assay (ELISA). Realtime-qPCR (RT-qPCR) and Western blot were used to respectively detect mRNA and protein levels. HDAC6 was up-regulated in brain I/RI mice (MCAO group), and down-regulated again in MCAO mice transfected with shRNA-HDAC6 (MCAO + shRNA group). The infarct area of the MCAO mice was increased, neurological scores were higher, and serum protein levels of 3-NT, 4-HNE and 8-OHdG were higher. HDAC6 interference attenuated above effects. Though protein levels of Nrf2 and HO-1 in cytoplasm increased slightly in MCAO group, they increased significantly by HDAC6 interference. The protein levels of Nrf2 in cytoblast decreased significantly in MCAO group, and increased markedly by HDAC6 interference. HDAC6 interference protected mice against experimental stroke-induced brain injury via Nrf2/HO-1 pathway